1. Field of the Invention
The invention relates in general to a network system, and more particularly to an analog/digital hybrid wireless network system for steering antenna beam and the method therefor.
2. Description of the Related Art
The wide use of adaptive antennas lies in their ability in reducing received interference and enhancing transmitted signal by direction finding and beam forming. This improvement in reception and transmission leads to an increase in capacity and extension in link range.
FIG. 1 shows a conventional network system with adaptive antennas. The network system 100 includes an antenna array 110, dual transceivers 120 and a processor 130. The network system 100 is connected to a network 140, in which the antenna array 110 receives/transmits signals from/to the network 140. Dual transceivers 120 are used for simultaneous transmitting signals to the network 140 or for simultaneous receiving signals from the network 140. The processor 130 includes a baseband processor (BBP) 132 and a media access control (MAC) 134. Further, the BBP 132 is embedded with digital beamforming function, such that signals from the network can apply appropriate complex digital weights.
The conventional network system 100 provides a simple architecture towards extending link range. However, the use of complex (or vector) weights as opposed to real (or scalar) weights in beamforming increases both complexity and difficulty in tuning for adaptivity. Additionally, the use of dual transceivers complicates the issue of amplitude and phase tracking. The task-specific and integrated BBP/digital beamforming/MAC combination of processor 130 also limits its flexibility for performance upgrades and structure expansion.
Accordingly, there is a need to provide a less complex and more flexible wireless network system to extend link range.